1. Field of the Invention
This invention relates to watch cases, and more particularly to a fluid-tight watch case of the type intended to contain a watch movement and a dial fixed to the movement, comprising a back including a peripheral wall, a bezel surrounding this wall, being removably attached thereto and including a holding element intended to keep the dial and the movement in place, a glass made of mineral material supported by the bezel, and an annular gasket compressed between the bezel and the peripheral wall of the back.
The current tendency to make increasingly thinner fluid-tight watches entails the production of watch cases made up of simplified components, which can easily be secured to one another, and provided with means for ensuring fluid-tightness and fastening means which are both as compact as possible.
In general, such watch cases may be round or non-round, and the glasses utilized are plane and made of a transparent mineral material such as mineral glass, or of a stone such as sapphire. Great care must be taken in fixing the glass to the bezel; and in most cases, in order to ensure fluid-tightness, a flat gasket is inserted between the periphery of the glass and the walls of the annular groove, called the snap, provided in the bezel for receiving the glass.
2. Description of the Art
The published U.K. Specification No. 2,012,458 A describes a watch case of the type initially mentioned wherein the bezel is in one piece and the gasket is disposed in an undercut in the peripheral wall of the back. This prior art design has made it possible to produce thinner watch cases then ever before. However, it has its limitations owing to the lessened rigidity of the bezel, for it has been found that if the thickness of the bezel is reduced beyond certain limits, the metals commonly used for the bezel no longer guarantee sufficient rigidity, the diameter of the watch having to remain the usual size in any event.
Thus, there is a need for a watch case in which the difficulty is overcome by means of a design which makes it possible to reduce the thickness of watch cases still further without appreciably lessening the rigidity of the component parts.
Watch case designs have been proposed in which the underside of the bezel includes a groove for receiving a gasket. Bezels of this kind are described in Swiss Pat. Nos. 443,158 and 386,934. However, these are round watch cases, and they are not designed for achieving extreme thinness. Hence these prior art designs do not suggest any solution to the problem set forth above.